Stockholm University swabs the Tube

Researchers at Stockholm University map microorganisms in the underground in collaboration with Stockholm County Council and SL (local transport of Stockholm county). 47 cities around the world, including New York, São Paolo and Shanghai, are part of the research project, called MetaSUB.

“We want to understand the composition of microorganisms in the underground environment. With further knowledge we can hopefully help to reduce the spread of pathogens”, says Klas Udekwu at the Department of Molecular Biosciences, The Wenner-Gren institute, Stockholm University. He coordinates the Swedish part of the project together with his colleague Per Ljungdahl.

Klas Udekwu and his assistants collect samples using nylon buds that they rub against various surfaces in the underground for at least three minutes. DNA is extracted so that researchers can identify the microorganisms and their content of specific genes such as antibiotic resistance. The first swabbing takes place on March 15 to 18, but samples will be collected periodically from all underground stations in Stockholm during the five year long project. Extraction and analysis are done at Stockholm University, which will also help to analyse samples from other cities.

Knowledge creates 'smart cities'

Klas Udekwu. Photo: Stockholm University.

“With the help of modern methods in metagenomics we can now, at molecular level, begin to understand the dynamics of organisms in the cities. Increased knowledge can have a positive impact on sustainability, security and future planning. This includes the basis for the ‘smart cities’ of the future, cities that can detect and react to levels of pathogens”, says Klas Udekwu.

“There are many questions that interest us. We examine, for example, how the environment and the microbe colonies change with weather, seasons and the flow of people. By combining our data with information on the urban environment, it would be possible to examine whether the composition of microorganisms, for example, varies depending on access and proximity to hospitals. That could contribute to better community planning”, he says.

Research collaboration with Stockholm County Council

“The environment in the underground is very special. It consists of man-made caves with high air supply and a large flux of people. In many cities, the underground is the main way of transportation. That is why we begin our study there”, says Klas Udekwu.

In addition to the aim of contributing to urban planning, researchers hope that data from MetaSUB will create a new resource for discovering new biochemical pathways, small molecules and antibiotics produced by the ecosystem of microorganisms. This is interesting because the microorganisms both have learned to and evolved to live among us humans. In New York, the first city studied in MetaSUB, the researchers found roughly the microorganisms they expected. The majority of them do not cause disease and some even help to break down toxins.

The project is part of Stockholm University’s research collaboration with Stockholm County Council.

About MetaSUB

MetaSUB is a consortium of laboratories around the world working to identify microorganisms in the underground system. The research project started in New York by researchers at Cornell University and now covers the underground systems of 47 cities and involves some hundred researchers worldwide.